Loud speaker



may 4', 192s.

7 C. W. PETERSCN nous SPEAKER Filed Dec.. 10, 1924 CIMA, W. RIJ-(min:y

April 22nd, 1924, now in the reissue. division,- I have shown a'device for transpos- Patented May y 4, 1926.

UNITED STATES vlnr-4i PATENT oFFlcE.

camas w. ramasox, or .um moa, mexican.'

noun suma.

Anuman and December 1o, im. semi n. 755,055.

2'0 all twhom it may concern:

Be it lrnown that I. CHARLES W. Pamsoiv, Aa citizen .of the United States, and aresldent of Ann Arbor, in the county of 'Washten'aw' and Stateof Michigan, have ers.

United States Patent No.' 1,491,208,

iuiglelectrl- 'c vibrations into sound vibrations, w 'ch is essentially, a pair of E-shaped magnete, with an amature of resilient nature held between the central arms, which are formed.y as a north and a south pole.I The pscillating ilux is impressed :o n the armature itself, which is of magnetic material, both' fluxcreatingcoils impressing the same polarity on the central part of the amature. The center lies between the 'two central arms of the magnets, and vibrates as the uxvarigs." The vibration i'n the form shown i's transmitted by a rod mounted on the armature, which ,rod extends through a hole in-one of the magnets. v .v

'Ihe object of my present invention is to improve upon the mechanical features of the device of my loud speaker.v I. have shown and my 'devices are f a conical diaph designed to give` results with such a diaphragm, but vit will beunderstood that this is not the only type of diaphragm which can be -used. y.

Among my objects is the improvement of the'link system transmitting the motion of this amature to the diaphragm. The ends of the-armature are still held between the yokes or side arms of the two magnets, but the center of the armature is in my new 1mprovement connected to one arm of a piv* .oted lever. This lever in turn transmits the motion ofthe amature to the diaphragm at the proper let'erarm distancey from the fulcrum point. In the'type shown in the drawings, the long lever arm is connected to the armature and short lever arm. at right angles to the first, is connected to thecenter of a cone diaphragm giving a motion of less amplitude and greater force to the dlaphragm than that of the armature itself.

` hereinafter more 'part of this specification:

This reduction of motion and" lincrease of force 1s very desirable in connection with cone type diphragms. Having the two lever Varma at right an les .as shown permits of a more compact an ethcient construction than if the two were in zline. In case -t'he two lever arms are equal the diaphragm vibrate with lthe same amplitu e as the armature, the same as when the two are connected by` a straight rod link, but the lever link has greater sturdiness and various constructional advantages in my device.

Alnother of my multaneously a slmple way to afl]ust the ar mature into its central osition in the air gap, and a simple and e cient fulcrum for the lever. Thisobje'ct I have accomplished by the use of a resilient spring fulcrum, ya, screw anda depression in the mounting surface so arranged that while tightening the vscrew the air gap ila-adjusted.

objects is toprovide siy It is my object with relation to the struc; I

ture to be used, to make it simple, and effective,.and hence economical of production,

easy to'- repair, and of great permanence 1n use..

A'I accomplish my object by that certain construction and arrangement of part't'o be specifically pointed out and claimed.

Referring now to the drawing forming AFigure 1 represents a front view of my assembled device.

Figure 2. represents a vertical section taken along the lines 22.l ooking inthe direction of the arrows in Figure 1. i

Figure 3 represents a front lview of the arfl mature box 3 with the cover; plate and the magnet cover of insulating material removed, as on the line 3-3 of Figure 2.

There is provided a base 1 which for ornamental reasons may be oval. From the base an upright supporting member 2 di vides into two arms 2 in a Y`shaped formation. The upper armsof the Y are joined with :a horizontal piece 3, on which is suplported the armature box 4. From the posi perspectivev iieldlpole 'and whose ends 'are magnetically close tp the outer arms of the E-shaped field magnets, amature coils around the parts of the'armature between this center pole and arm of the field magnet, fa diaphragm, and

a lever link systemto transmit the vibration ofthe amature to the diaphragm at desired amplitude or conversely `to transmit the vilbrbtion of the diaphragm to the' armature at desired amplitude. l

72 Aloud s eaker comprising two opposed y E-shaped fiel y magnets Ywith the center poles separated by an air gap andmagnetized N and S respectively, a resilient armature whose center plies the air gap between the center field poles and whose ends are ma netically close'jo the-outer arms of the 8. In an apparatus used to convert audio I electrical varlations into sound vibrations,-

or sound Ivibrations into electric excitations,

the combination of a magnet element, op-

posite poles thereof forming an air gap between them, an armature in the air gap, a diaphragm and a right angled link member connecting thev armature to the diaphragm and fulcrumed substantially at the apex of said rightanlglle.'

. C ARLES W; PETERSON. 

